Fibers

15 pages, 6673 KiB

Open AccessArticle

Enhanced Impact Strength of Ultra-High-Performance Concrete Using Steel Fiber and Polyurethane Grout Materials: A Comparative Study

by Ali Al-shawafi, Han Zhu, S. I. Haruna, Yasser E. Ibrahim and Saleh Ahmed Luqsum

Fibers 2024, 12(9), 77; https://doi.org/10.3390/fib12090077 - 23 Sep 2024

Viewed by 399

Abstract

This study examined the impact properties of ultra-high-performance concrete (UHPC) mixtures with steel fiber (SF) and retrofitted with polyurethane (PU) grouting using repeated drop-weight tests. Micro-steel fiber was added to UHPC mixes from 0 to 3% Vf, and PU grouting overlays of 5 [...] Read more.

This study examined the impact properties of ultra-high-performance concrete (UHPC) mixtures with steel fiber (SF) and retrofitted with polyurethane (PU) grouting using repeated drop-weight tests. Micro-steel fiber was added to UHPC mixes from 0 to 3% Vf, and PU grouting overlays of 5 mm, 10 mm, and 15 mm were applied. Digital image correlation (DIC) was used to analyze failure modes. The results showed significant impact durability and energy absorption improvements with increased SF content and thicker PU overlays. UHPC-15PU exhibited 363% and 449% higher first crack and failure strengths than UHPC-5PU. DIC analysis confirmed the failure patterns of the U-shaped UHPC specimen under impact load conditions. Full article

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19 pages, 1922 KiB

Open AccessArticle

Modern Insulation Materials for Sustainability Based on Natural Fibers: Experimental Characterization of Thermal Properties

by Beata Anwajler

Fibers 2024, 12(9), 76; https://doi.org/10.3390/fib12090076 - 18 Sep 2024

Viewed by 670

Abstract

The recycling of materials is in line with the policy of a closed-loop economy and is currently an option for managing waste in order to reuse it to create new products. To this end, 3D printing is being used to produce materials not [...] Read more.

The recycling of materials is in line with the policy of a closed-loop economy and is currently an option for managing waste in order to reuse it to create new products. To this end, 3D printing is being used to produce materials not only from pure polymers but also from their composites. Further development in this field seems interesting and necessary, and the use of recycled materials will help to reduce waste and energy consumption. This article deals with the use of degradable waste materials for the production of insulating materials by 3D printing. For the study, samples with different numbers of layers (one and five), composite thickness (20, 40, 60, 80, and 100 mm) and composition (including colored resins that were transparent, black, gray, and metallized, as well as resins that were colored gray using soybean oil and gray using natural fibers) were made. The role of natural fillers was played by glycerin and biomass ash with a weight ratio of 5%. The finished materials were tested, and the values of the coefficient of thermal resistance and heat transfer were determined. The best thermal properties among the tested materials were distinguished by a five-layer sample made of soybean-oil-based resin with a thickness of 100 mm. This sample’s heat transfer coefficient was: 0.16 W/m²K. As a material for thermal insulation in 3D printing technology, biodegradable components have great potential. Full article

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39 pages, 2751 KiB

Open AccessSystematic Review

Sustainable and Naturally Derived Wet Spun Fibers: A Systematic Literature Review

by Cristiana Pereira, Tânia V. Pinto, Raquel M. Santos and Nuno Correia

Fibers 2024, 12(9), 75; https://doi.org/10.3390/fib12090075 - 16 Sep 2024

Viewed by 786

Abstract

Increasing economic and environmental concerns arising from the extensive exploration and dependence on fossil fuel-based materials have encouraged the search for eco-friendly alternatives. Fibers based on biomass-derived materials have been attracting growing interest. Among other features, the mechanical performance of bio-based fibers needs [...] Read more.

Increasing economic and environmental concerns arising from the extensive exploration and dependence on fossil fuel-based materials have encouraged the search for eco-friendly alternatives. Fibers based on biomass-derived materials have been attracting growing interest. Among other features, the mechanical performance of bio-based fibers needs to be improved to effectively compete with their counterparts and emerge as viable substitutes. This review presents scientific advancements in the development of naturally derived fibers, and strategies for their production with tailored mechanical properties. The potential of natural precursor-based fibers for their conversion into high-performance carbon fibers is also emphasized. Studies reporting the mechanical properties of bio-based fibers developed by wet spinning are identified, analyzed, and discussed. These studies show that cellulose is the most studied material, while Ioncell technology is identified as the most suitable method for producing cellulose-based fibers with the highest tensile strength. Studies have also demonstrated that silk fibroin exhibits tensile strength and elongation at break ranging from 300 to 600 MPa and 30 to 50%. Although several novel processes have been explored, there are still challenges that need to be addressed for bio-based fibers to become feasible options, and to boost their usage across industries. Full article

(This article belongs to the Collection Review Papers of Fibers)

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12 pages, 3565 KiB

Open AccessArticle

Rapid Monitoring of Scale Precipitation and Inhibition in Geothermal Fluid Using Optical Fiber Sensor Based on Surface Plasmon Resonance

by Ai Hosoki, Kifuyu Sugiura, Takuya Okazaki, Heejun Yang, Hideki Kuramitz, Akira Ueda and Amane Terai

Fibers 2024, 12(9), 74; https://doi.org/10.3390/fib12090074 - 4 Sep 2024

Viewed by 474

Abstract

An optical fiber scale sensor based on the detection principle of surface plasmon resonance (SPR) was developed for the rapid, high-sensitivity, real-time evaluation of scale precipitation in geothermal fluids. The optical fiber SPR scale sensor was fabricated by depositing a gold thin film [...] Read more.

An optical fiber scale sensor based on the detection principle of surface plasmon resonance (SPR) was developed for the rapid, high-sensitivity, real-time evaluation of scale precipitation in geothermal fluids. The optical fiber SPR scale sensor was fabricated by depositing a gold thin film onto the surface of an optical fiber with an exposed core. The optimal gold film thickness of the sensor was determined to be 30 nm, which achieved a refractive index sensitivity of 2140 nm per refractive index unit. A field test was conducted using geothermal brine from the Obama Binary Geothermal Power Plant in Unzen, Nagasaki Prefecture. A conventional optical fiber scale sensor and the SPR sensor were simultaneously assessed using raw and pH-adjusted brines. For the SPR sensor, a peak shift of 0.27 nm/min was observed at a response time of 1 min, whereas no change in transmittance was observed for the conventional sensor until 180 min. After the experiments, a scanning electron microscopy-energy-dispersive spectroscopy analysis was conducted on the sensors, and the findings showed that the deposition of Mg-SiO₂ scale did not significantly differ between the two sensors. The developed SPR sensor achieved faster scale precipitation detection (tens of minutes to hours) than the conventional sensor. Full article

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17 pages, 8649 KiB

Open AccessArticle

Green Biobased Polyethylene Terephthalate (bioPET) Composites Reinforced with Different Lengths of Basalt Fiber for Technical Applications

by Stanisław Kuciel and Karina Rusin-Żurek

Fibers 2024, 12(9), 73; https://doi.org/10.3390/fib12090073 - 30 Aug 2024

Viewed by 768

Abstract

This paper presents the modification results and effects of reinforcing green polyethylene terephthalate matrix composites (bioPET ECOZEN^® T120) with basalt fibers of two different lengths. Five types of composites with two filling levels of 7.5 and 15 wt% of each fiber were [...] Read more.

This paper presents the modification results and effects of reinforcing green polyethylene terephthalate matrix composites (bioPET ECOZEN^® T120) with basalt fibers of two different lengths. Five types of composites with two filling levels of 7.5 and 15 wt% of each fiber were produced by injection molding. Basic mechanical and processing properties, microstructure photographs, and reinforcement effects were analyzed and low- and high-cycle fatigue tests were performed. A significant increase in strength and stiffness was observed (especially for short fibers) proportional to the amount of fibers; longer fibers would also increase the deformation capacity of the composite. Furthermore, longer fibers would reduce relaxation processes (creep) but would not increase the dissipation capacity and mechanical energy. Predictability of fatigue effects enables optimal environmentally friendly materials to be designed. Full article

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27 pages, 13471 KiB

Open AccessFeature PaperReview

Potential Valorization of Banana Production Waste in Developing Countries: Bio-Engineering Aspects

by Robert Waraczewski and Bartosz G. Sołowiej

Fibers 2024, 12(9), 72; https://doi.org/10.3390/fib12090072 - 24 Aug 2024

Viewed by 1296

Abstract

Plant food production generates a lot of by-products (BPs). These BPs are majorly discarded into the environment, polluting it, or into landfills where they just decompose, providing no benefit and taking up storage space, causing financial costs. These plant BPs are biodegradable, but [...] Read more.

Plant food production generates a lot of by-products (BPs). These BPs are majorly discarded into the environment, polluting it, or into landfills where they just decompose, providing no benefit and taking up storage space, causing financial costs. These plant BPs are biodegradable, but reusing them may provide a better outcome and profit. The vast majority of plant-based food BPs are polysaccharide polymers like gums, lignin, cellulose, and their derivatives. It is possible to utilize plant food production waste, like banana peels, leaves, pseudostems, and inflorescences, to produce bioethanol, single-cell protein, cellulase, citric acid, lactic acid, amylase, cosmetics, fodder additives, fertilizers, biodegradable fibers, sanitary pads, bio-films, pulp and paper, natural fiber-based composites, bio-sorbents, bio-plastic, and bio-electricity in the agro-industry, pharmaceutical, bio-medical, and bio-engineering fields. Moreover, the use of banana BPs seems to be a way of dealing with many issues in underdeveloped countries, providing a clean and ecological solution. The suggested idea might not only reduce the use of plastic but also mitigate waste pollution. Full article

(This article belongs to the Collection Review Papers of Fibers)

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Graphical abstract

19 pages, 5314 KiB

Open AccessArticle

Comparative Analysis and Evaluation of Modeling Methods for Nuclear-Grade HEPA Filters

by Ali Al Dabbas, Mohammed Al-Azba, Katalin Kopecskó, Mohammad Fawaier, Ahmad Alshebli, Laith Al-Hyari and Aurélie Joubert

Fibers 2024, 12(9), 71; https://doi.org/10.3390/fib12090071 - 23 Aug 2024

Viewed by 585

Abstract

High-Efficiency Particulate Air (HEPA) filtration plays a crucial role in maintaining air quality in critical environments such as lean rooms, hospitals, and nuclear facilities. The point of this study is to look into how well nuclear-grade HEPA filters work and behave by looking [...] Read more.

High-Efficiency Particulate Air (HEPA) filtration plays a crucial role in maintaining air quality in critical environments such as lean rooms, hospitals, and nuclear facilities. The point of this study is to look into how well nuclear-grade HEPA filters work and behave by looking at the main ways they catch particles using two modeling methods to figure out how well the filters work overall. This study encompasses particles with diameters ranging from 0.05 to 5.00 µm and a density of 1500 kg/m³. The current study systematically examined key parameters such as particle size, fiber diameter, and filtration velocity, which revealed their significant influence on the HEPA filter efficiency. Notably, the most penetrating particle size (MPPS) is identified within the expected range of 0.1–0.3 µm for both approaches. A critical threshold in fiber diameter is discovered when it exceeds 0.85 µm, resulting in a substantial shift in particle penetration and overall collection efficiency. This study also explored the impact of filtration velocity on filter performance, demonstrating increasing deviations as velocity rises, following a polynomial trend. The current study also rigorously validated the model predictions against experimental data from uranine particle filtration tests, confirming the model’s accuracy and applicability. These findings provide essential insights for optimizing the design and operation of nuclear HEPA filters, emphasizing the necessity of considering the particle size, fiber diameter, and filtration velocity. Both modeling approaches exhibit a negligible 0.04% deviation in the MPPS efficiency, which increases polynomially with the filtration velocity. Importantly, both approaches consistently identified the same MPPS regardless of the filtration velocity. Additionally, the model reinforces the substantial impact of fiber size on filter efficiency. A comprehensive comparison with the experimental data yielded closely aligned results with a maximum deviation of 1.14%. This validation strengthens the model’s ability to elucidate the underlying physical phenomena governing the influence of filtration velocity on efficiency, making it a valuable tool in nuclear HEPA filter research and development. Full article

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Fibers, Volume 12, Issue 9 (September 2024) – 7 articles

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